The present invention relates to mineral mining installations and more particularly to apparatus for controlling the position of a mineral mining machine movable along a guide. One example of control apparatus of this kind is shown in German Patent Specification No. 2319910.
One form of known apparatus has hydraulic piston and cylinder units connected between the machine guide and elongate beams capable of pivoting in relation to the guide. The beams are connected to roof supports at their ends remote from the guide and serve as an abutment for the guide. It is known to utilize composite resilient bars or rods as the beams and each beam then has its bars connected via a connector and a bracket to the goaf side of a scraper-chain conveyor having the main machine guide at its mineral-face side. At the opposite ends the bars connect to a guide which locates in a slidable manner with a floor structure of one of the roof supports which is usually a self-advancing support with individually movable frames. In the case of self-advancing supports the floor rails of the frames would have guideways into which the guide connected to the bars slidably engage. The guide thus couples the floor rails together and this per se inhibits the floor rails from adapting themselves to any unevenness in the floor level. Moreover some adaptation of the supports or their floor structures to accept the guides is necessary and with known forms of apparatus there are limitations on the type of the supports and hitherto the apparatus has not been readily applicable to supports having a single floor-engaging part. Another disadvantage of known apparatus is that in general extensive adjustability is not possible.
A general object of this invention is to provide an improved form of apparatus.